1. Field of the Invention
The present invention relates to a novel aminoalkylcyclopropane derivative having an antagonistic activity with respect to N-methyl-D-aspartic acid (hereinbelow, referred to as "NMDA") receptor. More particularly, the present invention is concerned with a novel optically active aminoalkylcyclopropane derivative, a racemic modification thereof, or a pharmaceutically acceptable acid addition salt of the optically active aminoalkylcyclopropane derivative or racemic modification thereof, which has remarkably high antagonistic activity with respect to NMDA receptor, as compared to known aminomethylcyclopropane derivatives and is useful as a preventive agent for cerebral infarction and a protective agent against ischemic diseases.
2. Discussion of Related Art
It has been known that 1-phenyl-2-aminomethylcyclopropane derivatives, such as 1-phenyl-1-diethylaminocarbonyl-2-aminomethyl-cyclopropane hydrochloride (common name: Milnacipran) [hereinafter, referred to as "compound (A)"], represented by the following formula (A): ##STR2## are useful for treating central nervous system neuropathy, and especially effective for treating neurotic depression and psychogenic neurosis (Examined Japanese Patent Application Publication No. 63-23186).
It has also been known that the above-mentioned compound (A) has an activity to inhibit the synaptosomal uptake of norepipephrine and 5-HT, which activity is known as anti-depression activity (Neuropharmacology, Vol. 24, No. 12, 1211-1219, 1985). It has also been known that the above-mentioned 1-phenyl-2-aminomethyl-cyclopropane derivative has an antagonistic activity with respect to NMDA receptor and is useful as a cell protective agent against ischemic brain cell damage (Unexamined Japanese Patent Application Laid-Open Specification No. 3-56415).
In the development of pharmaceutical products, it has been an important task to develop a compound having high antagonistic activity with respect to NMDA receptor, as compared to known compounds.